<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* ol li {
            color: red;
        } */
        /* .red {
            color:red;
        } */
        /* li {
            color: red;
        } */
        /* .hobby li {
            color: red;
        } */
         li  a {
            color: red ;
         }
    </style>
</head>
<body>
     <ul>
         <li>吃饭</li>
         <li>睡觉</li>
         <li>打豆豆</li>
     </ul>
     <ol class="hobby">
         <li class="red">吃饭</li>
         <li class="red">睡觉</li>
         <li class="red">
            <a href="#">吃饭</a>
         </li>
          
     </ol>
</body>
</html>